|The medical and financial costs associated with termination of a nutrition support nurse
|Goldstein M, Braitman L E, Levine A M
This is a critical abstract of an economic evaluation that meets the criteria for inclusion on NHS EED. Each abstract contains a brief summary of the methods, the results and conclusions followed by a detailed critical assessment on the reliability of the study and the conclusions drawn.
The use a nutrition support nurse (NSN), within a nutrition support team, who was responsible for patients receiving total parenteral nutrition (TPN).
Economic study type
The study population comprised patients receiving TPN.
The setting was secondary and tertiary care. The economic study was carried out in the USA.
Dates to which data relate
The effectiveness, resource use and cost data were gathered in the fiscal years (FYs) 1992 to 1998. The price year was 1992.
Source of effectiveness data
The effectiveness evidence was derived from a single study.
Link between effectiveness and cost data
The costing was carried out retrospectively on the same sample of patients as that used in the effectiveness study.
The use of power calculations was not reported. All patients receiving both enteral and parental nutrition, identified at the authors' institution during the FYs 1992 to 1998, were included in the effectiveness study. The overall sample consisted of 1,093 patients receiving TPN. There were 162 patients in FY 1992 (with NSN), 176 patients in FY 1993 (without NSN), 204 patients in FY 1994 (without NSN), 172 patients in FY 1995 (with NSN), 139 patients in FY 1996 (with NSN), 123 patients in FY 1997 (with NSN), and 117 patients in FY 1998 (with NSN). It appears that no patient has been excluded from the analysis. The demographics of the patients were not reported.
The authors stated that this was a quasi-experimental reversal design of the form On-Off-On (On and Off referred to when there was and was not an NSN, respectively). During the Off period, a nutrition support team dietician mainly took the role of the NSN and assumed responsibility for the assessment and monitoring all TPN individuals. Patients were identified and the outcomes were assessed retrospectively from a review of the hospital charts. The study was conducted in a single centre, the Albert Einstein Medical Center in Philadelphia (PA), USA. The length of follow-up was not reported. No loss to follow-up appears to have occurred.
Analysis of effectiveness
All of the patients included in the initial study sample were considered in the analysis of effectiveness. The outcomes used in the study were four indicators of inappropriate care:
the rate of patients on TPN with functional gastrointestinal (GI) tract (suggesting inappropriate TPN),
the number of days of inappropriate TPN,
the rate of TPN patients with line sepsis, and
the number of TPN bags wasted.
The authors did not compare the demographics and clinical characteristics of the two groups. However, they stated that there were no major changes in total inpatient admissions, the average age of all inpatients at the hospital, and the average severity index over time. This suggested that clinical activity at the study centre was relatively stable from 1992 to 1998.
The rate of patients on TPN with functional GI tract (inappropriate TPN) was 4.3% in FY 1992 (NSN on), 12.5% in FY 1993 (no NSN), 11.8% in FY 1994 (no NSN), 9.3% in FY 1995 (NSN on), 13.7% in FY 1996 (NSN on), 7.3% in FY 1997 (NSN on), and 8.5% in FY 1998 (NSN on).
Overall, the rate of patients on TPN with functional GI tract was 8.6% with an NSN present versus 12.1% without an NSN present (95% confidence interval, CI: -0.06 - 3.6; p=0.069).
The number of days of inappropriate TPN were 90 in FY 1992 (NSN on), 197 in FY 1993 (no NSN), 221 in FY 1994 (no NSN), 99 in FY 1995 (NSN on), 105 in FY 1996 (NSN on), 82 in FY 1997 (NSN on), and 104 in FY 1998 (NSN on). Overall, there was a statistically significant difference during the time periods with and without an NSN, (p<0.05).
The rate of TPN patients with line sepsis was 12.3% in FY 1992 (NSN on), 17% in FY 1993 (no NSN), 9.8% in FY 1994 (no NSN), 5.8% in FY 1995 (NSN on), 9.4% in FY 1996 (NSN on), 5.7% in FY 1997 (NSN on), and 11.1% in FY 1998 (NSN on). Again, there was a statistically significant difference during the time periods with and without an NSN, (p=0.028).
The number of TPN bags wasted was 0 in FY 1992 (NSN on), 8 in FY 1993 (no NSN), 11 in FY 1994 (no NSN), 5 in FY 1995 (NSN on), 2 in FY 1996 (NSN on), 1 in FY 1997 (NSN on), and 3 in FY 1998 (NSN on).
The effectiveness study showed that the termination of an NSN post led to inappropriate care, as shown by significantly more days of inappropriate TPN and a significantly higher rate of patients with line sepsis.
Measure of benefits used in the economic analysis
The health outcomes were left disaggregated and no summary benefit measure was used in the economic analysis. In effect, a cost-consequences analysis was conducted.
Discounting was not relevant since the costs per patient were incurred during a short time. The unit costs were reported but the quantities of resources used were not. The health services included in the economic evaluation were TPN, lipids, multivitamins, enteral feeding, sepsis, line insertion, consult for line, radiology, catheter insertion equipment, dressing change kit, intravenous tubing, serum glucose monitoring, and laboratory test protocol. These items were estimated for all FYs considered in the study. Then, charges in the FYs without NSN were compared with the FYs with NSN in order to derive the costs of inappropriate nutrition. It was assumed that enteral feeding would have been given in place of inappropriate TPN. The financial outlay of the hospital consisted of the NSN's salary plus 22% benefits per annum.
The cost/resource boundary of the hospital appears to have been used. Resource use was estimated using actual data that referred to the sample of patients included in the effectiveness study. Actual hospital charges, which appear to have been derived from the hospital database, were used but a yearly cost-to-charge was then applied to estimate the actual costs. The cost of sepsis was estimated from two published studies and two different values (maximum and minimum estimates) were considered in the analysis. The price year was 1992, but no adjustment for inflation was made.
Statistical analysis of costs
The costs were presented as average values. Kolmogorov-Smirnov tests, to compare the preventable charges in the two study periods (NSN on versus NSN off), were conducted.
The indirect costs were not considered.
Sensitivity analyses were not performed.
Estimated benefits used in the economic analysis
See the 'Effectiveness Results' section.
Excess preventable charges and costs were estimated. These considered the rate of inappropriate TPN, line sepsis, and TPN wastage with and without an NSN, multiplied by the respective unit costs.
The estimated total excess charges with a minimum estimate of $1,400 per episode of sepsis were: $84,490 in FY 1992 (NSN on), $173,648 in FY 1993 (no NSN), $158,074 in FY 1994 (no NSN), $78,492 in FY 1995 (NSN on), $91,010 in FY 1996 (NSN on), $57,568 in FY 1997 (NSN on), and $78,717 in FY 1998 (NSN on), (p=0.001). The corresponding figures with a maximum estimate of $40,000 per episode of sepsis were $856,490 in FY 1992 (NSN on), $1,331,648 in FY 1993 (no NSN), $930,075 in FY 1994 (no NSN), $464,492 in FY 1995 (NSN on), $592,810 in FY 1996 (NSN on), $327,769 in FY 1997 (NSN on), and $580,517 in FY 1998 (NSN on), (p=0.001).
When charges were converted to actual costs, the estimated excess preventable costs with a minimum value of $1,400 per episode of sepsis were $38,148 in the year after termination, and there was a reduction in costs of $34,485 after reinstatement of the nurse. The corresponding figures with a maximum value of $40,000 per episode of sepsis were $194,285 in the year after termination, and there was a reduction in costs of $156,654 after reinstatement of the nurse.
Considering the financial outlay of the hospital, the institution's employment cost for the NSN was comparable to the estimated preventable costs when the minimum cost estimate for sepsis was used.
Using the maximum cost estimate for sepsis, the preventable costs were three to four times NSN compensations.
Synthesis of costs and benefits
The costs and benefits were not combined as a cost-consequences analysis was carried out.
Costs, episodes of inappropriate total parenteral nutrition (TPN), and sepsis were fewer during the years when a nutrition support nurse (NSN) was present in the hospital than during the years when the NSN was not present. The excess preventable costs due to inappropriate TPN, line sepsis and TPN bags wastage without an NSN were one to four times higher than the NSN compensation.
CRD COMMENTARY - Selection of comparators
The choice of the comparators was appropriate since it reflected the changes in care patterns for patients receiving TPN at the study hospital. You should decide whether they are valid comparators in your own setting.
Validity of estimate of measure of effectiveness
The analysis of effectiveness used a retrospective observational study. This was selected in order that the actual changes in care patterns that were implemented at the authors' institution, could be assessed. However, the use of a prospective randomised study would have been appropriate. A potential limitation related to the design of the study was the fact that the groups were not studied concurrently. Factors other than the study intervention could have affected the results of the analysis, although the authors showed that no major institutional changes were observed over time. The study sample consisted of all consecutive patients and was representative of the study population. Patient demographics were not reported, which would have been interesting. The authors acknowledged that the study may have been underpowered in view of the small number of events observed each year.
Validity of estimate of measure of benefit
No summary benefit measure was used in the analysis because a cost-consequences analysis was conducted.
Validity of estimate of costs
The perspective of the study was implicitly that of the authors' institution. All the costs related to TPN and relevant to the hospital were considered in the analysis. A breakdown of the items was provided and the unit costs were reported along with the price year. This would facilitate both replication and reflation exercises in other settings. Statistical tests were conducted when the cost estimates were compared during the two study periods. No adjustment for inflation was made, although this may have been relevant due to the long timeframe of the study. The authors stated that all the prices were expressed in 1992 values. This could have led to an underestimation of the savings associated with NSN care. The authors also noted the difficulties in attributing costs to single financial centres. The cost estimates were specific to the study setting, but two different estimates were used for sepsis costs due to wide variations observed in the literature. The cost calculations were conservative as some items, which could have favoured NSN care, were not considered.
The authors made some comparisons of their findings with those from other studies, but did not address the issue of the generalisability of the study results to other settings. All of the estimates were specific to the authors' institution and sensitivity analyses were not carried out. Therefore, the external validity of the analysis was low. The study referred to patients requiring TPN and this was reflected in the authors' conclusions.
Implications of the study
The study results showed that an NSN proved to be a clinically relevant member of a multidisciplinary team for TPN, necessary to ensure quality of care and cost-savings. Further studies should corroborate the findings of the present evaluation.
Goldstein M, Braitman L E, Levine A M. The medical and financial costs associated with termination of a nutrition support nurse. Journal of Parenteral and Enteral Nutrition 2000; 24(6): 323-327
Other publications of related interest
ChrisAnderson D, Heimburger DC, Morgan SL, et al. Metabolic complications of total parenteral nutrition: effects of a nutrition support service. JPEN: Journal of Parenteral and Enteral Nutrition 1996;3:206-10.
Trujillo EB, Young LS, Chertow GM, et al. Metabolic and monetary costs of available parenteral nutrition use. JPEN: Journal of Parenteral and Enteral Nutrition 1999;23:109-13.
Subject indexing assigned by NLM
Cost-Benefit Analysis; Employment; Hospital Costs /statistics & Humans; Nursing Service, Hospital /economics /manpower; Nursing Staff, Hospital /economics /supply & Outcome Assessment (Health Care) /statistics & Parenteral Nutrition, Total /economics /nursing /standards; Patient Care Team /economics; Quality Assurance, Health Care; Retrospective Studies; Sepsis /epidemiology /nursing /prevention & control; distribution; numerical data; numerical data
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Date abstract record published